(1) Field of the Invention
The present invention relates to a fuel cell composite plant in which a fuel cell power generation plant and an argon gas manufacturing plant are combined.
(2) Description of the Prior Art
With regard to a conventional power generation plant comprising a fuel cell, for example, a phosphoric acid type fuel cell, its one example will first be described in reference to FIG. 3 of accompanying drawings.
In FIG. 3, a fuel cell body 1 comprises a fuel pole (anode) 1a, an air pole (cathode) 1b and an electrolyte (phosphoric acid) 1c interposed therebetween. A material gas and oxygen (or air) are fed from a material gas production system 2 and an oxygen gas holder 3, respectively, to a reforming device 4, where a reaction is then performed in order to form a hydrogen-rich gas having a hydrogen concentration of about 70%. The thus formed hydrogen-rich gas is afterward delivered to the above-mentioned fuel pole 1a through a valve 5.
On the other hand, the above-mentioned air pole 1b is supplied with air from which dusts have been removed by an air filter 6 and a pressure of which has been raised by means of an air compressor 7.
In the fuel cell body 1 thus constituted, an energy transformation efficiency of chemical energy into electric energy is about 50%, and the remaining portion of the chemical energy therein is transformed into thermal energy, which is afterward radiated in a cooling section 1d. Air which will function as a refrigerant is fed from the above-mentioned air compressor 7 to a cooling section 1d through a valve 8, and after cooled by means of a heat exchanger 9, the air is circulated by an air circulator 10.
A part of air from the air compressor 7 is also used for drive starting and for make-up.
The respective portions of the hydrogen-rich gas and air are consumed for the reaction in the fuel cell body 1, and unreacted gases discharged from the fuel pole 1a via a valve 11 and from the air pole 1b are employed as a fuel for a gas turbine 12 and air for combustion.
Eventually, these gases are discharged out of the system, after utilized to drive the gas turbine 12. When the plant is at rest, the valves 5 and 11 are operated to feed a nitrogen gas from a nitrogen gas holder 13 to the fuel pole 1a via a valve 14 and to thereby replace the hydrogen-rich gas therein with the fed nitrogen gas.